Fiber strip splicer for taping machines

ABSTRACT

The invention relates to a fiber strip splicer for taping machines, formed by two mobile assemblies comprising respective modules ( 6, 6′ ) between which the capture for joining the fiber strip ( 3 ) that is being fed to the application process and a strip ( 3 ′) intended to continue with the supply when the first strip ends is possible, the modules ( 6, 6′ ) incorporating heating means ( 10 ) to activate the fiber strips in the joining, a blade for cutting the excess of the finished fiber strip ( 3 ) after the joint, and a catch ( 16 ) for securing the end of the new fiber strip ( 3′ ) on standby for the joining.

FIELD OF THE ART

The present invention relates to the application of synthetic fiber strips by means of taping machines on surfaces or jigs with the geometry of the parts to be manufactured, and particularly to the application of individual fiber strips by means of an applicator head for applying multiple strips at the same time from respective feed reels, proposing a splicer for automatically joining the strip coming from a reel that is ending and the strip coming from a new feed reel.

STATE OF THE ART

The industry for manufacturing parts formed by synthetic fibers, such as carbon fiber or glass fiber, is applied to produce increasingly larger parts and in larger amounts. This requires adapting the productivity of the taping machines with which the fiber material is applied.

To that end, machines have been developed with applicator heads simultaneously applying multiple fiber strips, forming application webs reducing the necessary number of runs and therefore the time for manufacturing the parts, thus solving the limitations conditioned by a low application speed.

The increase of the performance of the applicator heads for applying the fiber strips has made certain aspects, such as the fiber strip feed system, acquire a main role in the overall performance of taping machines due to the following reasons:

-   -   Upon eliminating the main bottleneck of taping machines, which         was the capacity of dispensing the material to be applied, there         are other factors which now become productivity limiting         factors, such as the downtimes necessary for reloading the tape         reels as they run out.     -   The high productivity of the head generally requires high         speeds, accelerations and dynamics in the supply of the fiber         strips, such that the feed must be able to supply the material         in the conditions and at the pace required by the applicator         head, maintaining the control of the tension required in the         application.     -   Since the optimal productivity is sought for each application,         the width of the application web is large in many cases, which         requires design criteria and precautions stricter than those         usually used for handling narrower webs.

Up until now, the feed reels in the heads of machines for applying fiber strips were replaced by stopping the machine and splicing the strips of the finished reel and of the new feed reel manually, since there were no automatic splicers in this field of synthetic fibers.

However, in a high performance machine it may be necessary to change the reels every five or ten minutes, each reel change requiring, by means of the manual process, a machine downtime of the same order, which conditions idle times that considerably limit the productivity of the machines.

OBJECT OF THE INVENTION

According to the invention, an automatic splicer for joining fiber strips is proposed, whereby the downtime for replacing fiber strip feed reels in machines for applying said strips is virtually eliminated.

The proposed splicer determines a fiber strip circulation passage, defined by pulleys determining two arrival paths for arriving at the circulation passage in opposing positions, respective modules being on the sides of the path for the passage through the splicer, which modules can move closer to or away from the central area through which the fiber strip passage is formed, each of which modules is provided with heating means, cutting means and means for capturing the end of the fiber strips.

Said arrangement allows the fiber strip which is being supplied to the application process to pass freely through the splicer, and allows preparing the fiber strip of a new feed reel in a standby position without interrupting said supply, such that when the reel of the fiber strip which is being supplied ends, the splicer automatically joins the fiber strip of the reel on standby with the fiber strip of the reel that is ending, the splicing being carried out in a very short time (about 2 seconds), therefore stopping the machine for that purpose has virtually no effect on productivity.

The process for joining the fiber strips in the indicated splicing operation is carried out by means of positioning the fiber strips to be joined in mutual contact, with pressure on the joint and heat supply, which is carried out by means of moving the mobile modules of the splicer close to one another, between which modules the fiber strips are caught with a controlled pressure, while at the same time the heating means of the modules themselves supply the heat necessary to activate the resin of the fiber strips so that they are adhered to one another.

In this splicing operation, the cutting means of the module located on the side of the fiber strip coming from the finished reel further cut said fiber strip in order to separate the excess thereof, such that when the modules are separated again, the fiber strip feed continues with the supply from the new reel, with the joint having virtually no effect on the application.

At the front of the modules, between which the fiber strips to be joined are caught, there are mutual insertion conformations by means of a recess in one of the modules and a corresponding projection in the other module, such that when the pressure for joining the fiber strips is applied, the assembly of such strips is located inside said insertion, thus preventing the width from being altered by the effect of the pressure for the purpose of maintaining the suitable conditions for the application, because it is critical for the width of the assembly of the supplied fiber strip to be uniform for this purpose.

The arrival paths of the fiber strip towards the circulation passage through the splicer are formed through tilt pulleys determining a drive of the fiber strips that absorbs the oscillations of said strips due to the unwinding thereof in the corresponding reels.

With the proposed splicer, the fiber strips are further joined with an overlapping section of the fiber strips of the order of 50 millimeters, which is within the overlapping section specifications of between 25 millimeters and 125 millimeters, so that the joint is sufficiently resistant and allows its adaptation to the curvature of the passage though the drive pulleys without altering the supply towards the application.

Due to the foregoing, said head object of the invention has certainly advantageous features, acquiring its own identity and a preferred character for joining fiber strips in processes for manufacturing parts by means of taping with said strips.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of the structural assembly of the splicer object of the invention.

FIG. 2 shows an enlarged perspective view of one of the parts of the splicer, with the elements of the corresponding mobile module in an exploded arrangement.

FIG. 3 shows an enlarged perspective view of the other part of the splicer, with the corresponding mobile module assembled.

FIG. 4 shows a perspective view of the splicer feeding a fiber strip from a feed reel and with the fiber strip coining from another reel in a standby preparation process.

FIG. 5 shows a perspective view similar to the previous one, with a reel arranged in a standby situation and the reel whereby the feed being supplied is ending.

FIG. 6 shows the arrangement of the splicer at the time the fiber strips of the finished reel and the new reel on standby are joined.

FIG. 7 shows the arrangement of the splicer at the opening time, after the fiber strips are joined, to continue the feed with the supply from the new reel.

FIGS. 8A, 8B and 8C schematically show a sequence of the process for joining two fiber strips by means of the mobile modules of the splicer.

DETAILED DESCRIPTION OF THE INVENTION

The object of the invention relates to a splicer intended to automatically join fiber strips in processes for manufacturing parts by taping by means of applying said fiber strips, for the purpose of establishing the continuity of the fiber strip feed supply to the application processes by means of joining the fiber strip coming from a feed reel that is ending and the fiber strip of a new reel continuing the supply.

The proposed splicer structurally consists of a frame (1) on which there are joined pulleys (2) driving the fiber strips in a circulation passage towards the application process thereof.

The path of the fiber strips towards the circulation passage through the splicer is formed from two feed supply directions, for the path for the passage of respective fiber strips (3, 3′) coming from respective feed reels (4, 4′) which can be independently arranged on respective shafts (5, 5′).

At the entrance of the path of the fiber strips (3, 3′) to the splicer, from the two feed supply directions, there are arranged respective entrance tilt pulleys (2.1) which allow absorbing the orientation oscillations of the fiber strips (3, 3′) at their supply arrival from the corresponding reels (4, 4′) due to the unwinding, such that said arrival orientation oscillations do not affect the circulation passage of the fiber strips (3, 3′) through the splicer.

On both sides of this circulation passage of the fiber strips (3, 3′) through the splicer, there are arranged respective modules (6, 6′) which are assembled by means of corresponding runners (7, 7′) on a guide (8), having respective movement actuators (9, 9′) which allow independently actuating the movement of said modules (6, 6′) closer to and away from the passage area of the fiber strips (3, 3′). For this purposes, the actuators (9, 9′) can be pneumatic, magnetic, mechanical type actuators, etc.

Each of the modules (6, 6′) is provided with heating means formed by one or more electric resistances (10) housed near the front oriented towards the passage area of the fiber strips (3, 3′), as well as cutting means formed by a blade (11) which can emerge from said front oriented towards the passage area of the fiber strips (3, 3′) and has an actuator (12) for forward and backward movement.

In the mid-part, under the passage area of the fiber strips (3, 3′), there is arranged a block (13) determining at the upper part several planes on which the modules (6, 6′) can be supported, elastic dollies (14) being arranged in these planes of the block (13), the blades (11) of the modules (6, 6′) impinging against such dollies, in the position of these modules against the mentioned planes of the block (13). To adjust the position of the block (13), so that the modules (6, 6′) are suitably supported on the upper planes thereof, said block (13) can move vertically, having a vernier (15) which allows placing it at the suitable height.

With all this, the passage of a fiber strip (3) coming from a feed reel (4) and directed towards the application can be formed through the splicer, such that while said fiber strip (3) is being supplied, another reel (4′) can be incorporated and the fiber strip (3′) thereof can be prepared in a standby arrangement on the module (6′) of the same side, as shown in FIG. 4, in order to splice the fiber strip (3) with the fiber strip (3′) on standby when the reel (4) ends, for the purpose of continuing the feed supply towards the application from the new reel (4′).

For the standby preparation of the corresponding strip (3, 3′), the modules (6, 6′) are provided with a catch (16) incorporated in an adjustable manner on a support (17) tilting on a base (18) such that the end of the fiber strip (3, 3′) to be arranged in a standby position can be caught in the corresponding module (6, 6′) with said catch (16) by means of manual actuation.

When the fiber strip (3, 3′) oil standby is captured in this arrangement by means of the corresponding catch (16), the respective module (6, 6′) moves until being supported against the block (13), whereby the fiber strip (3, 3′) on standby is perfectly fixed in that positions, as shown in FIG. 5.

In such conditions, when the reel (4) supplying the fiber strip (3) which is being sent to the application process ends, the module (6) located on the side of this fiber strip (3) moves towards the module (6′) in which the fiber strip (3′) on standby is prepared, the two fiber strips (3 and 3′) being captured between both modules, as shown in FIG. 6.

When the modules (6, 6′) move close to one another, the base (18) of the catch (16) of each of them impinges with a front-side protrusion (18.1) on the catch (16) of the other module, making it tilt in a slight elevation, whereby the fiber strips (3, 3′) are completely free from the action of the mentioned catches (16), thus achieving a perfect contact between them.

The fiber strips (3, 3′) are captured between the modules (6, 6′) with a controlled pressure (of the order of 2 bars), and at the same time, the capture area is heated (of the order of 50° C.) by means of the resistances (10) of the modules (6, 6′), whereby the resin of the fiber strips (3, 3′) is activated such that said fiber strips (3, 3′) adhere to one another.

During the capturing action, the blade (11) of the module (6) corresponding to the fiber strip (3) of the finished reel (4) moves forward, the excess of said fiber strip (3) thus being cut against the corresponding elastic dolly (14) at the level of the joint with the new fiber strip (3′).

During said process for joining the fiber strips (3, 3′) the machine is stopped, but the productivity is not significantly affected due to the very short time (about 2 seconds) that the splicing operation last. Nevertheless, to prevent the feed supply to the fiber strip application process from being stopped, it is possible to incorporate a storage solution after the splicer in order to provide the feed supply therefrom to the application process during the splicing of the fiber strips in replacing finished feed reels.

Once the fiber strips (3, 3′) are spliced, the modules (6, 6′) are separated, the joint being released such that the feed supply to the application process continues with the fiber strip (3′) coming from the new reel (4′), as shown in FIG. 7. At this time, the excess of the finished fiber strip (3) can be removed and a new reel can be placed on the shaft (5) in order to prepare the fiber strip thereof in a standby arrangement on the module (6) for a subsequent change of the feed reel when reel (4′) ends.

A device (19) is furthermore arranged at the outlet of the splicer, whereby the tension of the fiber strip (3, 3′) leaving towards the application process is regulated in order to keep this tension constant, thus maintaining the suitable conditions for the application.

These suitable conditions for the application also require the width of the fiber strip which is applied to be constant, for which purpose the modules (6, 6′) of the splicer determine mutual insertion conformations on their front opposing faces, the module (6) having, for example, a projection (20), and the module (6′) having a reciprocal recess (21) in correspondence with the width of the fiber strips (3, 3′) and in the direction thereof.

Therefore, as can be observed in the sequence of FIGS. 8A, 8B and 8C, during the splicing, the fiber strips (3, 3′) are compressed between said conformations (20 and 21), such that in the splicing operation, the joint section of the fiber strips (3, 3′) is inserted in the recess (21), wherein the material is prevented from being deformed towards the sides due to the pressure exerted for the joining, the joint therefore being maintained with the same width as the fiber strips (3, 3′) spliced together. 

1. A fiber strip splicer for taping machines, of the type comprising two opposing mobile assemblies, between which a fiber strip (3) that is being fed to the application and a fiber strip (3′) intended to continue with the feed supply when the first fiber strip (3) ends can be caught, characterized in that the mobile assemblies for capturing the fiber strips (3, 3′) to be joined consist of respective modules (6, 6′) which can move along a guide (8) by means of respective linear actuators (9), each of said modules (6, 6′) incorporating heating means (10) in relation to the part opposing the passage area of the fiber strips(3,3′), a cutting blade (11) which can impinge by means of forward and backward movement on said passage area of the fiber strips (3, 3′) and a catch (16) which allows securing the end of the fiber strip (3′) intended to be joined with the fiber strip (3) which is being supplied to the application process, whereas in the mid-area there is arranged a block (13) determining at the upper part planes on which the modules (6, 6′) can be supported, elastic dollies (14) against which the blades (11) of said modules (6, 6′) impinge being incorporated in said planes.
 2. A fiber strip splicer for taping machines according to claim 1, characterized in that the block (13) can move vertically by means of a vernier (15) for adjusting its position for the purpose of supporting the modules (6, 6′) on the upper planes thereof.
 3. A fiber strip splicer for taping machines according to claim 1, characterized in that the catch (16) of the modules (6, 6′) is incorporated in an adjustable manner on a support (17) which can be tilted on a base (18), said base (18) having a front-side protrusion (18.1) whereby it impinges on the catch (16) of the opposite module (6, 6′) when said modules (6, 6′) are closed moving closer to one another, in order to place the mentioned catches (16) in an inoperative raised position while the modules (6, 6′) are closed moving closer to one another.
 4. A fiber strip splicer for taping machines according to claim 1, characterized in that the modules (6, 6′) have reciprocal insertion conformations, according to a projection (20) in one module and a respective recess (21) in the other module, between which conformations the fiber strips (3, 3′) are captured in the operation for joining them, such that the housing of the assembly in the recess (21) during the joining action prevents the material from being deformed towards the sides.
 5. A fiber strip splicer for taping machines according to claim 1, characterized in that tilt pulleys (2.1) are arranged in the drive of the fiber strips (3, 3′) towards the passage through the area comprised between the modules (6, 6′), which pulleys absorb the oscillations of said fiber strips (3, 3′) in the arrival orientation as a result of the unwinding in the corresponding feed reels. 